Industrial Boiler Maximum Achievable Control Technology


EPA initially finalized rules that would reduce emissions of air pollutants from existing and new Industrial Boilers and Process Heaters, Commercial and Industrial Solid Waste Incinerators (CISWI), and Sewage Sludge Incinerators (SSI) on March 21, 2011. EPA received robust comments on its March 21, 2011 rule, as a result EPA proposed several rule changes based on additional data provided after the agency issued final standards and after conducting additional analyses. Subsequently EPA decided to reconsider parts of the Boiler and CISWI rules. The reconsideration resulted in EPA issuing proposed amendments on December 2 3, 2011 for the major, area source Boiler and CISWI rules. The effective date of the rule was May, 20, 2011, but EPA issued No Action Assurance letters (in effect until December 31, 2012) for certain initial deadlines.

On January 31, 2013 EPA finalized maximum achievable control technology standards for existing and new Industrial Boilers and Process Heaters, Commercial and Industrial Solid Waste Incinerators (CISWI), and Sewage Sludge Incinerators (SSI), which were originally finalized in March 2011. Existing units have until January 31, 2016 to comply with the rules emission limits. Sources may request an additional year to comply from the permitting agency if they are installing controls or repowering.

The compliance date for new sources is January 31, 2013, or upon startup, whichever is later. Since the rule has changed several times, new sources have a period of 3 years from publication of the final rule to comply with alternate limits before they must comply with the finalized new source limits.

In a separate but related action, EPA revised the non-hazardous secondary materials rule (NHSM). This rule defines which materials are, or are not, “solid waste” when burned in combustion units. The NHSM rule helps determine which standards; either boiler or CISWI, a unit that burns these materials will be required to meet.


Affected Sources:
The boilers and process heaters that would be covered by these standards do not burn solid waste. There are approximately 14,000 major source boilers in the US. Approximately, 12% (1,700) would be required to install emission control technology if they do not already meet the emission limits. Boilers affected under this rule burn natural gas, fuel oil, coal, biomass (e.g., wood), refinery gas, or other gas to produce steam.

The amended rule adds to and refines the list of subcategories for light and heavy industrial liquids to reflect design differences in the boilers that burn these fuels. The final rule set new emissions limits for PM that are different for each solid fuel subcategory (e.g., biomass, coal) to better reflect real-world operating conditions. In addition, based on the number information the rule set new emissions limits for carbon monoxide. The proposal seeks to allow for alternative total selective metals emission limits to regulate metallic air toxics instead of using a PM as a surrogate. Work practice standards would replace numeric emission limits for dioxins. Additional changes include amendments to the compliance monitoring provisions, allowing CO stack testing or continuous monitoring.

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